The Animal Tumor Models and Histopathology Shared Resource operates within the setting of an existing institutional resource, the Veterinary Service Center (VSC), that was established in 1994 at the School of Medicine. The faculty supporting this Shared Resource are all experts in basic research and experienced in animal modeling, experimental design, veterinary pathology, mouse reproductive technologies and rodent health surveillance;they will significantly enhance the quality of research for Cancer Center members and their Programs. The interdisciplinary nature of cancer biology and biomedical research requires considerable expertise to conduct quality in vivo research. The Animal Tumor Models and Histopathology Shared Resource provides this expertise in the form of consultation in animal modeling, comprehensive analysis of lesions in animal models, diagnostic clinical pathology, and the availability of high quality mice in order to eliminate confounding experimental variables. As an academic institutional resource, the facility provides services to Stanford investigators at full cost recovery. As a Shared Resource for the Cancer Center, this facility will provide these services to advance in vivo cancer biology at reduced, and therefore more accessible, rates to member scientists engaged in cancer-related research. In addition, the facility will introduce tumor modeling biomethodologies as new services.